An automotive door comprises inner and outer door panels that define a relatively shallow depth therebetween. A window regulator together with its requisite hardware must fit within this constrained space. For example, U.S. Pat. No. 5,987,819 illustrates a representative window regulator. The regulator typically includes a window drive assembly that converts rotational motion from a motor or handheld crank to translate one or more cables that control the opening and closing movement of the window. In order to the limit the size of the regulator, it is helpful to minimize the depth or profile of the drive system, whether the motive source be electrical or mechanical.
PCT Publication No. WO 01/14673 describes a window drive system for automotive applications. This system includes a counter-balance spring that functions to reduce torque requirements when the window is moved upwards. The size of this drive system is minimized by placing the counter balance spring on the shaft of a crown gear that drives a cable-guiding drum.